'Everyone is dead' in Germanwings crash: local police

There is no hope of finding any survivors on board the doomed Germanwings airline that crashed in a remote area of the French Alps on Tuesday, police said.

"There is no need for any rescue operations, everyone is dead," said a police officer in the town of Le Vernet, near the crash site.

He said it was virtually impossible that survivors would be found among the 144 passengers and six crew on board the Airbus flight from Barcelona to Duesseldorf.

The area had been "sealed off for the start of the investigation," he added.

French Prime Minister Manuel Valls said a helicopter that reached the crash site confirmed there were no survivors.

He also said authorities have not determined the cause of the crash.

A crisis cell has been set up by authorities in Le Vernet, located in the Blanche valley between the towns of Digne-les-Bains and Barcelonette.

Interior Minister Bernard Cazeneuve was due to arrive at the centre later on Tuesday.

Seven police and civil security helicopters have been deployed to the area, where an emergency flight control centre has been established to organise the heavy air traffic to and from the crash site, according to a source close to the operation.

Around 360 emergency fire fighters in surrounding regions have been sent to the area to assist local forces.

Exceptional logistical material is also being rushed to the zone, including lighting to allow salvage operations to continue through the night.